How do you name acids? We'll learn how to look at the chemical formula for an acid and then write its name. We will focus on both acids without oxygen and also acids that contain oxygen, which are sometimes called oxoacids. In order to name an acid, you need separate the H+ from the negative ion. Then you figure out the name of the negative ion, and use rules for acid compound naming. If the negative ion ends in -ide, the acid is hydro- -ic acid. If the negative ion ends in -ate, the acid is -ic acid. If the negative ion ends in -ite, the acid is -ous acid. It's also important to note that there are some exceptions: phosphoric acid, phosphorous acid, sulfuric acid and sulfurous acid.